The present invention relates to an apparatus for identifying an anesthetic fluid container, said apparatus comprising at least two anesthetic fluid containers, which containers include at least a fluid chamber for an anesthetic fluid and which containers contain anesthetic fluids different from each other in terms of the chemical structure thereof. The apparatus further comprises a gas chamber for vaporizing the anesthetic originating from the fluid chamber and which gas chamber can be a part of the container or a chamber separated from the container. A connecting element couples the container with a conduit extending to a patient for supplying the anesthetic to a patient and which container is detachable from the connecting element and replaceable with another container possibly containing a different anesthetic fluid. A body member installs the container therein in view of coupling it by means of the connecting element with a conduit extending to a patient. The invention relates also to a method for identifying an anesthetic fluid container. Furthermore, the invention relates to a method and apparatus for detecting a connection between an anesthetic container and a conduit supplying a gas to a patient.